2. Field of the Invention
The invention relates to a three-dimensional integrated circuit and particularly relates to a three-dimensional integrated circuit different from the conventional structure.
2. Description of Related Art
In recent years, the electronic industry develops and prospers with the guidance of Moore's Law. However, with the increasing demand for higher operation speed of electronic products (e.g. portable electronic devices), technical challenges gradually emerge. In order to improve the functions of portable electronic devices to meet the demand, the technology of three-dimensional integrated circuit (3D IC) integration has been proposed as one of the solutions for developing portable electronic devices to be small-sized, highly efficient, multi-functional, and low power consuming, and low-cost.
The interconnection between chips is typically achieved using through-silicon via (TSV) technology, which is to manufacture vertical through vias passing through chips or wafers. It is the new 3D IC integration technology that accomplishes interconnection between the chips. Different from the conventional IC package technology and salient point stacking technology, the TSV technology achieves the greatest density of stacking chips in three-dimensional directions, has the smallest size, improves the speed of the devices, reduces signal delay, and suppresses power consumption. Therefore, TSV is the key technology for 3D IC integration.
For a three-dimensional integrated circuit that is mainly formed by stacking different wafers (or chips), the stack structure increases the overall heat resistance. Consequently, a heating phenomenon occurs when the three-dimensional integrated circuit is operated, which results in the increase of working temperature and decrease of reliability of the three-dimensional integrated circuit.
Two or more chips may be fixed to each other through an adhesive, which forms an adhesive bonding layer between the chips. However, the adhesive bonding layer has low thermal conductivity and reduces the heat dissipation efficiency of the three-dimensional integrated circuit. According to the current technology, a thermal TSV is used to dissipate the heat from the hot zone. Nevertheless, in the structure of the current three-dimensional integrated circuit, the thermal TSV is configured beside the hot zone and thus achieves very limited heat dissipation. In addition, microchannel cooling may also be utilized to dissipate the heat of the hot zone. However, the microchannel cooling has a larger structure and is not suitable for portable electronic devices.